4. Where do the names of the elements come from?
Some were named as substances before they were known to
be elements.
silver
47
sulfur
16
copper
29
Some are named from the natural substance that they are
found in.
borax
beryl stones
zircon
boron
5
beryllium
4
zirconium
40
Some elements were named after figures in mythology.
Thor
Prometheus
Pluto
thorium
90
promethium
61
plutonium
94
*notice that names of elements are not capitalized,
even if they come from names that are
Some elements were named after scientists.
Albert Einstein
einsteinium
99
Alfred Nobel
Ernest Rutherford
nobelium
102
rutherfordium
104
Some were named after the home of their discoverer or the place
where they were discovered (or made).
France
francium
87
Scandinavia
California
scandium
21
californium
98
5. What are the symbols that we use for the elements?
It's a little inconvenient to have to write out the names for
the elements all the time.
Dalton invented a set of symbols.
Why don't we use these?
it would be hard to come
up with 118 of them
no symbols on a keyboard
Today we use letters.
Some elements have only one capital letter.
sulfur
nitrogen
S
N
hydrogen
H
Some elements have a capital letter and a lower case letter.
calcium
magnesium
Ca
helium
He
Mg
Some elements have symbols that don't seem to match their
names because the symbols come from Latin:
mercury
silver
sodium
Hg (from hydrargyrum)
Ag (from argentum)
Na (from natrium)
others: antimony (Sb), copper (Cu), gold (Au), iron (Fe),
lead (Pb), potassium (K), tin (Sn), tungsten (W)
6. Which are the most common elements?
Known universe:
hydrogen 91%
helium 8.75%
all other elements 0.25%
Earth (crust, ocean, atmosphere):
oxygen 49.2%
silicon 25.7%
aluminum 7.50%
iron 4.71%
calcium 3.39%
sodium 2.63%
potassium 2.40%
magnesium 1.93%
hydrogen 0.87%
titanium 0.58%
chlorine 0.19%
phosphorus 0.11%
manganese 0.09 %
carbon 0.08%
sulfur 0.06%
barium 0.04%
nitrogen 0.03%
fluorine 0.03%
all others 0.49%
the human body
oxygen 65.0%
carbon 18.0%
hydrogen 10.0%
nitrogen 3.0%
calcium 1.4 %
phosphorus 1.0%
magnesium 0.50%
potassium 0.34%
sulfur 0.26%
sodium 0.14%
chlorine 0.14%
iron 0.004%
7. What do the elements look like in their pure form?
Of the 118 known elements, 21 have been found or made in such small
amounts that we can't be sure what they look like.
Two examples:
astatine (85)
- rarest naturally occurring element
- formed by radioactive decay of uranium or actinium
- longest half-life 56 seconds
- less than one teaspoon on the earth
copernicium (112):
- most recently named artificial element
- a single atom was made in 1996 by smashing zinc and lead
atoms together at a lab in Germany
- one more in 2000, two more in 2004
- named for Nicholas Copernicus on 19 February 2010, the
537th anniversary of his birth
That leaves 97 whose appearance we can talk about here.
There are two main divisions: metals and nonmetals
Which of the following elements are which? How can you tell?
aluminum
antimony
carbon
copper
oxygen
mercury
bromine
cadmium
fluorine
hafnium
phosphorus
sulfur
chromium
lead
zinc
zirconium
First we'll look at the metals: 74 elements
aluminum
hafnium
antimony
gold
cadmium
chromium
mercury
zinc
copper
zirconium
appearance: most metals are grayish-white shiny solids
exceptions: gold is bright yellow, copper is orange-red color
mercury is the only liquid
characteristics: shiny, conduct heat and electricity,
dent or bend when hammered,
opaque even when very thin
What about the nonmetals? 17 elements
oxygen
phosphorus
hydrogen
carbon
fluorine
sulfur
chlorine
iodine
bromine
selenium
gases: 11 elements
hydrogen, helium, nitrogen, oxygen, neon, argon, krypton, radon,
xenon are colorless; fluorine is yellow, chlorine is yellow-green
liquids: 1 element bromine
crystalline solids: 5 elements
phosphorus, sulfur, carbon, iodine, selenium
There are also some elements that are sort of in between metals
and nonmetals – we call them metalloids.
boron
silicon
arsenic
characteristics:
antimony
germanium
tellurium
solid, gray, sort of metallic looking, but shatter
when hammered and are semiconductors
Knowing whether an element is a metal, nonmetal, or metalloid in
its pure form will help us predict how it will form compounds!
Some elements have more than one form that they can be in
when pure.
carbon:
found at the surface of the earth
graphite
formed at high temperature and pressure
about 100 miles underground, carried up
by very deep volcanos
diamond
phosphorus:
white phosphorus
ignites spontaneously in air
used as a weapon of war
red phosphorus
doesn't ignite until it reaches
464o F; used in matches
When elements in their pure state have more than one physical
form, these are called allotopes.
Can you find any of the elements in their pure form in nature?
not very often – most are only found in compounds or
mixtures with other elements
Calcium is commonly found as a compound of calcium, carbon,
and oxygen called calcium carbonate. You can find it in
limestone, pearls, seashells, and dietary supplements.
Calcium in its pure form is not found naturally;
it can be obtained by electrolysis of calcium
compounds. It is a metal, and reacts with air.
Elements that can be found in pure form in nature are sometimes
called “native” elements.
gold nugget
native silver
native copper native platinum
iron meteorite native graphite rough diamond
native sulfur